PECARN Pediatric Head Injury Calculator

What Is the PECARN Pediatric Head Injury Rule?

The Pediatric Emergency Care Applied Research Network (PECARN) head trauma clinical prediction rule is a landmark, prospective derivation and validation study that establishes objective criteria to rule out clinically important traumatic brain injuries (ciTBI) in children presenting with acute blunt head trauma.

Why the PECARN Rule Matters

Computed tomography (CT) scans deliver ionizing radiation to developing pediatric brain tissue, which carries a non-trivial lifetime attributable risk of lethal malignancy. The PECARN algorithm achieves a negative predictive value exceeding 99.9% for identifying children at very low risk of ciTBI, safely sparing tens of thousands of children from unnecessary radiation and hospital stays.

Definition of Clinically Important TBI (ciTBI)

The PECARN study specifically defines a clinically important traumatic brain injury as:

• Death secondary to traumatic brain injury.
• Neurosurgical intervention (craniotomy, elevation of depressed skull fracture, intracranial pressure monitor placement).
• Endotracheal intubation for more than 24 hours for head injury.
• Hospital admission of 2 or more nights in association with traumatic brain injury on CT imaging.

Risk Categories by Age Group

1. Children Younger Than 2 Years (< 24 Months)

• High Risk (4.4% ciTBI risk): Glasgow Coma Scale (GCS) score < 15, signs of altered mental status (agitation, lethargy, somnolence, slow response), or palpable skull fracture. Head CT scan is strongly indicated.
• Intermediate Risk (~0.9% ciTBI risk): Non-frontal scalp hematoma (occipital, parietal, or temporal), loss of consciousness ≥ 5 seconds, severe injury mechanism (fall > 3 feet / 0.9 m, high-impact MVC, rollover, pedestrian struck), or parent states child is not acting normally. Clinical observation for 4 to 6 hours vs. immediate CT based on clinician assessment and parental preferences.
• Very Low Risk (< 0.02% ciTBI risk): None of the above criteria present. CT imaging is NOT recommended.

2. Children 2 Years and Older (2 to 18 Years)

• High Risk (4.3% ciTBI risk): GCS < 15, altered mental status, or signs of basilar skull fracture (raccoon eyes, Battle's sign, hemotympanum, CSF rhinorrhea/otorrhea). Head CT scan is recommended.
• Intermediate Risk (~0.9% ciTBI risk): History of loss of consciousness, history of vomiting, severe injury mechanism (fall > 5 feet / 1.5 m, high-impact MVC), or severe headache. Observation vs. CT scanning.
• Very Low Risk (< 0.05% ciTBI risk): None of the above criteria present. CT imaging is NOT recommended.

Related Emergency and Health Tools

Explore other clinical decision rules and medical calculators:

• Parkland Formula Calculator for burn trauma fluid resuscitation.
• PaO2/FiO2 Ratio Calculator for acute respiratory distress evaluation.
• Peak Flow Calculator for asthma zone management.